DEVELOPMENT OF THE SKULL IN THE OSTEICH TEIBE, 173 



and round (as in the Mole) of the superoccipital plate, and the persistence of the middle 

 part of the lambdoidal suture. 



Perhaps the most interesting part of these illustrations is the upper view (pi. 2. 

 tig. 1), for iiere are to be seen the greatest number of sutures. 



Only the middle third of the lambdoidal is to be seen ; but the sagittal and the coro- 

 noid are completely open, and show their teeth well. The parietals are aberrantly 

 large, as in the other "Struthionidse;" but the frontals, defrauded behind, are projected 

 further forwards than in typical birds, on account of the diminished size of the poste- 

 rior part of the nasals. An oval space, more than a line in length, appears in the 

 parietal part of the sagittal suture, nearer the coronal than the lambdoidal suture. 

 This is the famous lacertian " parietal fontanelle," which in the Apteryx appears for a 

 little time and then vanishes away. Even in the dense skull of the Blind-worm (Anguis 

 fragilis) this space will not fill up, but is a notable oval neat hole, and its constancy 

 in the Lacertilia is not a little remarkable. In examining the skull of an extremely 

 young Gecko*, I find that the great anterior fontanelle is lozenge-shaped, and that the 

 posterior angle is rounded (and the same condition is to be seen in Ilcematopus during 

 the first summer) ; this becomes the remnant of the originally large space which does 

 not fill up. Now there are certain groups of birds which approach the Reptiles 

 evidently, but not the Mammalia as well, as we see in the Ostrich-tribe ; amongst 

 these are the " Lamellirostres," from the hen-faced, free-toed Palamedeass, to the most 

 perfectly-toothed of living feathered types — the Goosanders [Merganser). The semi- 

 terrestrial species scarcely hide the fore paw in the wing ; these are the Geese and the 

 Screamers (Palamedea, Chauna). Now in the Geese and Swans the " parietal fonta- 

 nelle" of the Lizard reappears, and is often persistent; for in very old individuals the 

 anterior fontanelle is badly filled up. In the oldest and densest common Goose's skull 

 in my possession three of the angles of the original lozenge are still open, the posterior 

 of these being the counterpart of that in the adult Lizard. In the Common Duck 

 [Anas boschas) this structure may be seen during the first summer; it then fills up. 

 The upper view (fig. 1) of the Apteryx's skull shows well the extension forwards of the 

 parietals, and consequent shortening of the frontals, which, however, are themselves 

 developed much more anteriorly than in other birds ; for, as in the other Ostriches, 

 the nasals of the Apteryx are but narrow behind, and the exposed portion of the eth- 

 moid is only moderate, as in the Rhea. The long nasal part of the intermaxillaries, 

 as is usual in the tribe, ends in front of the lacrymal ; but this is not unlike what is 

 seen in those simpler types of the "Grallse" which have, like the Apteryx, long 

 bills, e. g. Tringa, Limosa, Numenius, Hoematopus. In most of these, these processes 

 are very delicate, and pointed towards the end ; but in the Hoematopus ostralegus each 

 moiety (in the young bird) ends separately in a flat lath-like flap ; this divergence of 

 these intermaxillary rami, with a rather persistent separateness, and their flat condition, 

 is exactly like what is shown in this figure of the Apteryx. This leaning, as it were, to 



* A Hemidactylus, from Barbadoes. 



